Belt.



W. STARRETT.

BELT.

APPucATloN FILED APR.18,I913

1,1 35,734. Patented Apr. 13, 1915.

vimini) STATES PATENT OFFICE.

WLLIAM sratrnrr, of MINEotI's; Minna/ser.

BELT.'

Specication of Letters Patent.

Y Patented Apr. 13, 1915.

Application med April 1a, 1913. serial No. 761,960;

. T0 all 'whom it may condem:

Be it known 'that I,W1LL1AM AS'rAluirkrr,

citizen of the United States, residing atf Minneapolis, in the county of'Hennepin and State of Minnesota, have invented certain new and useful Improvements in B'elts, of which the following is a specification.

My invention relates to belts and particularly to belts of that type in -which a number of thicknesses of leather or equivalent material are laid one upon the other for the purpose of increasin the weight and strength of thegbelt an necessarily, at' the same time increasing its thickness. The socalled triangular or V-slaped belts are necessarily formed in this manner and are oftenl thicker through in the radial lines lof curvature than thegreatest Width of the belt. Such belts have inv practice been foundv generally, unsatisfactory for the reason that the tension produced upon the outer layers of leather when the sam'e are bent about a pulley ofeven approximately small diameter becomes so tion of. the belt.' Furthermore', such` belts are so lacking in 'flexibility as to be incaable ofuse excepting on fairly lar e pul- There isian exteiiskive deman for a belt of the V-shape type tobe used as a drive belt on motor cycles,"but heretofore such belts when made'ofI lea'the'r or textile material have not proved satisfactory because" they' cannot= be run over the small pulleys used on motor cycles, or if run 'will' other means for securing together the several plies, said slots permitting the rivets to move along the same when the belt is sharply curved and thereby enabling the plies to have the aforesaid dili'erential movement which renders the belt flexible to prac- 'tically the extent that would Abe true of a single ply.

The full objects and advantages of my invention will appear in connection with the reat as to cause cracking of said oter layer' andiultimate destruc- .detailed description thereof .and are particularly pointed out in the claims.

In the drawings, illustrating the application of my invention in one form,-Figures 1 and 2 illustrate edge views of portions of a belt embodying my invention, part of the same being shown in section .through the lines of connecting rivets. Fig. 3 is a perspective View of. a fiat belt similar to that shown in Figs. 1 and 2. Fig. 4 is a perspective' view of a V-shaped or triangular belt of the same character.l Fig. 5 is anv edge View, partly in section, of a portion of a belt embodying my invention.

As shown in Fig. 1, I provide a belt having a central continuous ply 10, said central ply being Vfor'med with a lseries of longitudinalslots 11. On one side of said continuou's ply is a series of short belt sections 12, a similar series of belt sections 13 bein arranged on the other or inner side'o the belt.k .The inner sections 13 are in all cases spaced apa'rt at their ends a suitable distance, y'asy indicated at 14.` The outer sections 12 may, as indicated in Figs. 2, 3, and 4 at 15, be normally spaced apart a suitable distance, or may, as indicatedat 16 in Fig. 1, have the adjacent endsrin' contact when the belt extends inta straight line,` where there is but little curvature needed on the back of the belt.:l In Fig. 2, where the spaces 15 are leftbe'twee'n adjacent ends 'of the upper ply sections'the belt will have as great a flexibility in abackward direction as in a for- 'wartldectiom which may be of some advantage Where a belt tightener is employed, as indicated by the curvature in the belt in -Fig 2 and wherever there will be enough iexibility in the form shown in Fig. 1 to make practicable the employmentof a belt tightener. The outer plies or ply sections 12 and 13, as shown in Figs. 1", 2, 4 and 5, are secured in fixed relation to one another overand under the Ycentral ply 10 by means of rivets 17 extending through the slots 11 and firmly set in the ply sections 12 and 13. As shown in Figs. 1 and 2, the rivets 17 normally' extend through the centers of slots 11 when the belt is extended in a straight line. With the triangular form of belt ordinarily a single row of rivets and correspondingly a single row of slots in the con- A tinuous lt ply 10 is all that will be required. But for a fiat belt a plurality of rows of rivets 17 and of slots 11 will be required.

. pulley,

As shown in Fig. 5, the rivets 17 have the shanks thereof extending through slots 11 in contact with the ends of the slots nearest the ends of the top ply sections 12. This arrangement will permit differential movement of the plies when the belt is turned inwardly, but not when the belt is turned outwardly or toward the back.

The operation of my improved belt, whichever' form is employed, is the same in principle, namely, a relative slipping or differential movement between the different plies of the belt made possible by the provision of the slots in at least one of said plies through which the rivets extend, so that the ends of the sectional plies may and do actually move toward and away from one another as the belt is passed around a thus entirely withdrawing the tension strain from the outer plies due to the fulcruming efl'ect of the compression of material in the inner plies when the belt is being passed around a pulley. A

The objects of my improved belt are very apparent. It makes practicable the building up of a V-shaped or triangular belt, that is a belt in which the friction is effected by the sides thereof with the sides of a grooved pulley rim, which will be nearly if not quite as flexible as an ordinary fiat belt. Moreover, this result is effective by using for a large part of the weight of the belt short pieces of stock which might otherwise not be of great value. 1Where the invention is applied to flat belts, a belt of the requisite weight and strength may be provided also and which yet will have a high degree of flexibility and will be much less liable to injury from cracking and tension strain than would be the case if the same weight of mabv using considerable portions of short stock Y terial were combined to'make a belt of the same strength in which all the parts were integrally united.

I claim:

l. A belt comprising three independent strands or plies, of which the center strand or ply is continuous while the outer strands or plies are each formed of a series of short sections spaced apart at the ends, longitudinally alined slots being formed in the continuous strand or ply, and rivets fixedly secured in the outer sectional strands or plies and extending through the slots to permit differential relative movement of the strands or plies as the belt is curved in passing around a pulley.

2. A belt comprising three independent Strands or plies, of which the center strand or ply is continuous while the outer strands or plies are each formed of a series of short sections spaced apart at the ends, longitudinally alined slots being formed in the continuous strand or ply, there being two such slots for each section of the sectional strands or plies, and rivets fixedly secured in the sectional strands or plies and extending through the slots in such position that the shanks of the rivets will engage the end walls of the slots adjacent the ends of the upper sections of the belt to hold the strands or plies together and permit differential relative movement of said strands or plies, said differential movement taking place only when the belt is inwardly curved.

In testimony whereof I affix my signature in presence of two witnesses.

- WILLIAM STARRETT. 

